Abstract: An apparatus includes a take-up downstream from a heating surface for advancing corrugated paperboard sheet along a path of travel adjacent the heating surface; an initial sheet feeder for initially feeding a leading portion of the corrugated paperboard sheet along the path of travel; and sliding contact assemblies positioned opposite the heating surface for slidably contacting and applying pressure to urge the advancing corrugated paperboard sheet against the heating surface. Accordingly, heat is transferred from the heating surface to the moving corrugated paperboard sheet and without a conventional conveyor belt. The pressure applied by the sliding contact assemblies may be released when the initial sheet feeder is feeding the leading portion of the corrugated paperboard sheet. The apparatus may also generate a gas cushion to thereby reduce friction between the heating surface and the corrugated paperboard sheet when initially feeding the leading portion of the corrugated paperboard sheet.

Abstract: An paperboard making apparatus includes at least one heating plate having opposing first and second surfaces; at least one electrically powered heater positioned adjacent the first surface of the heating plate; and a take-up for advancing a corrugated paperboard sheet along a path of travel adjacent the second surface of the heating plate so that heat is transferred to the advancing corrugated paperboard sheet. The electrically powered heater preferably includes a base, and an electrical heating element on the base. The base is preferably mounted so that the electrical heating element is positioned in closely spaced relation from the first surface of the heating plate so that the electrical heating element radiates heat to the heating plate. Accordingly, conventional steam heating chests are not used and their associated drawbacks are overcome. Method aspects of the invention are also disclosed.

Abstract: A corrugated paperboard manufacturing apparatus includes preheaters, a double-facer, a cutter, and a board edge profile sensor downstream from the cutter for sensing a profile of a cut edge of a cut panel. A processor controls the double-facer and the preheaters responsive to the board edge profile sensor to thereby reduce warp in the cut panels. The board edge profile sensor is preferably an optical sensor, and, more preferably, may be a camera. Accordingly, near real time feedback may be used to adjust the upstream process to produce high quality paperboard. The board profile sensor also preferably further includes an associated scanner for optically or mechanically scanning the cut edge of the cut panel. A conveyor preferably carries the cut panels away from the cutter and toward a stacker. The board edge profile sensor may be positioned adjacent the conveyor or the stacker. Method aspects of the invention are also disclosed.

Abstract: A corrugated paperboard manufacturing apparatus includes one or more preheaters upstream from the double-facer for preheating the component sheets for the corrugated paperboard. A preheater preferably includes an electrically powered heater positioned adjacent a second surface portion of a preheater body for heating the preheater body so that heat is transferred to the component sheet contacting a first surface portion of the body. The first surface portion of the preheater body contacts the component sheet as the component sheet is advanced along the path of travel. The electrically powered heater is positioned adjacent the second surface portion of the preheater body for radiantly heating the preheater body. The temperature of the component sheet delivered to the double-facer from the preheater can be readily controlled to ensure high quality corrugated paperboard. In one embodiment, the preheater body may be provided by a rotating roll.